Crankshaft grinder



July 24, 1934. c, H, CRAFT CRANK-SHAFT GRINDER Filed Sept. 11, 1931 sSheets-Sheet 1 July 24, 1934.

Filed Sept. 11, 1931 C. H. CRAFT CRANKSHAFT GRINDER 3 Sheets-Sheet 2gwmmlioz C: if Crc ft July 24, 1934. c. H. CRAFT 1,967,744

CRANKSHAFT GRINDER Filed Sept. 11, 1931 3 t s t 3 ullil 23 Patented July24, 1934 cnanxsnsr'r cnmmza Clarence H. Craft, Uniontown, Pa., assignorof one-half to Wallace Miller, Uniontown, Pa.

Application September 11, 1931, Serial No. 562,399

' Claims. (CL 51-241) v This invention relates to grinding apparatusand'especially to a grinding device for crankshaft journals.

One of the primary objects of the invention :5 resides in the provisionof a grinding apparatus which may be mounted on the crank-case of anordinary automobile engine and grind the crankshaft bearings withoutremoving the shaft from the engine.

Another object of the invention consists in the provision of a device ofthis type with the necessary adjustments to adapt it to crank shafts ofvarious dimensions and to provide the precision necessary to work ofthis type.

Other objects and advantages of the invention will be apparent from thefollowing description when taken in connection with the accompanyingdrawings, in which,

Figure 1 is a perspective view of the apparatus supported from thecrank-case of an automobile engine.

Figure 2 is an end viewof the apparatus with a portion of the engineblock shown in vertical section.

Figure 3 is an enlarged sectional detail view through a crankshaft andshowing the suspend gig means for the grinding apparatus in posi- IFigure 4 is a vertical sectionalview through 80 the lower portion of theoperating shaft of the grinding apparatus.

Figure 5 is an elevational view of the upper part of the operatingshaft, grinding disc andrelated parts, and

36. Figure'6 is an enlarged detail view of one form of attaching meansfor supporting a portion of the apparatus. Referring tothe-drawings inmore detail, the numeral 1 indicates any conventional type of intemalcombustion engine provided with an upper 8 of any preferred materialwhich is mounted on a shaft 9. I will now describe the construction bywhich the grinding wheel 8 and its shaft 9 are suspended from thecrankshaft so as toper- 'vided with a set screw 30 for securing it inoperamit an accurate grinding and truing of the bear ing '7 and willthereafter describe the details of the mounting of the shaft 9 and itsadjustments. The drip pan being disconnected from the flanges 3 of thecrank-case and removed, brackets 10 provided with downwardly andoutwardly directed arms 11 are bolted to one of the flanges 35 by meansof bolts 12 as indicated in Figures 1 and 2. Adjustably mounted on therods 11 as by means of set screw 13 are sleeves 14 which carry angularlyarranged sleeves 15. The sleeves 15 form a support for a shaft 18 whichis adiustably secured in the sleeves 15 by set screws 16'. The angulararrangement of the respective sleeves 14-15 is such that by reversingtheir 7 positions, that is, by placing the sleeves 14 on the shaft 16and the sleeves 15 on the arms 11, the position of the shaft 16 may bealtered to suit varying conditions in engine construction.

A rod 17 is provided for suspending the grinding mechanism from thebearing to be ground, and this rod is provided with a hooked upper end18 and flat portions 19 adapted to rest on the bearing as indicated inFigures 1 and 3. This hooked portion of the suspending means is alsopreferably provided with a wiper 20 which is adapted to removegrindings, etc., from the hearing so as to prevent any interference withthe proper grinding and truing of the bearing.

Adjustably supported on the rod 17 is a duplex 86 sleeve comprisingthesleeve members 21 and 22, the latter being provided with set screws 23by means of which it is secured to the rod 17. Permanently secured tothe sleeve 22 as by means .of web 24 is sleeve 25.

This sleeve 25 is arranged at right angles to the sleeve 22 and formsone support for a hori-' ,0 zontally arranged pivot shaft 26. Theopposite end of the shaft 26 is supported by one of the piston rods 6 ofthe engine. For this purpose the piston of the particular piston rod isremoved and the shaft 26 is passed through eye 27 of the piston rod. Inorder to properly center the shaft 26 with respect to the eye 2'1 of thepiston rod and to rigidly secure these elements together, clamping andcentering means 28 and 29 are provided. These members are provided withfrustoconical ends adapted to be projected into the interior of the eye27, and the member 28 is protive position on the pivot shaft 26. Themember 29 is preferably threaded onto a sleeve 31 which is slidablymounted on shaft 26 and may be secured in adjusted position by a setscrew 32. This member 29 is provided with a handle 33 by means of whichit may be rotated on. the sleeve 31 so as to tightly wedge its conicalend into eye 2'7. By this construction it will be apparent that theshaft 26 is accurately centered with respect to the eye or bearingsleeve 27 of the particular piston rod 6 and that it is firmly held withrespect thereto. It will be obvious therefore that the pivot shaft 26 isdirectly suspended, from the crankshaft 4 at two difierent points andthat the suspending means including the rod 17 is adjustable so that theshaft 26 may be supported in parallel relation to the crankshaft 4 andin the same vertical plane.

In the grinding of a bearing '7 it will be understood that the grindingwheel 8 is moved back and forth longitudinally of the hearing as thewheel is being rotated by its motor A, and in order to define the extentof longitudinal movement of the wheel 8, sleeves 34 and 35 areadjustably mounted on the pivot shaft 26 as by means of set screws 36and 37. These sleeves when properly spaced and secured on the shaft 26will limit the movements of the sleeve 25 and hence the longitudinalmovement of the wheel 8 so as to allow it to grind the full length ofthe bearing 7 and the fillets connecting the bearing with the arms ofthe crankshaft.

In the grinding of a bearing '7 by the rapid rotation of the grindingwheel 8 it will be understood that the crankshaft 4 must be slowlyrotated in its bearings, and it is for the purpose of'maintaining theproper relation between the wheel 8 and bearing '7 during this rotationof the crankshaft that secondary shaft 16 heretofore described isprovided. This shaft forms a pivotal support for two connecting rods 38which have their opposite ends pivotally supported on the pivot shaft26. It will be apparent therefore by reason of these connecting rods 38,that the proper alignment of the shaft 26 beneath the bearing 7 ismaintained at all times with the result that'the grinding wheel 8 isaccurately guided back and forth along the length of the bearing 7.

It is desirable that the bearing being ground be supplied with water orother liquid, and to this end a pump 39 is supported on the shaft 26 bymeans of a sleeve 40. This pump is provided with a flexible diaphragm 41adapted to be occasionally depressed by a finger of the operator therebyforcing liquid through a flexible tube 42. This tube is connected at itsopposite end with a nipple 43 which is secured into a passage 44 formedin the hooked end 18 of the supporting rod 17. The passage 44 isprovided with a discharge outlet 45 which permitsthe liguid to drop ontothe bearing from which the grinding wheel is suspended. It will beunderstood that the diaphragm 41 is only operated from time to time asdeemed: necessary by the mechanic attending the grinding operation.

The drive shaft 9 of the grinding apparatus extends through a casing 50and is provided adjacent its upper and lower ends with thrust bearings51 and 52; the latter being located in a head 53 secured to the casingof the motor A. The shaft 9 of course is rigidly connected with themotor shaft at its lower end and has the grinding wheel 8 rigidlysecured to its upper end. The cylindrical casing 50 for the shaft 9 isrigidly secured within a cylindrical jacket 54 by means of a nut 55which is threaded onto the upper end of the jacket 54 and causes theslitted end of the latter to securely grip the casing 50. The nut 55 isprovided with a lateral extension 57 which encircles the supporting rod17 and is caused to releasably grip the same by means of a. clamping nut58. The casing 54 is also secured to the rod 17 by means of the duplexsleeves 21 and 22 heretofore referred to and which are clamped to therod 1'7 by the set screws 23. A nut 56 serves to secure the sleeve 22 tothe jacket 54.

A micrometer adjustment for the jacket 54 consists of a threaded sleeve59 which is threaded to the lower end of the jacket 54. This sleeve isprovided with an internal annular shoulder 60 which rests upon anexternal shoulder 61 formed on a sleeve 62 slitted at its lower end,which sleeve is secured to the casing 50 by means of a tapered nut 63.The lower end of the micrometer 59 is internally threaded for thereception of a wedging nut 64 which serves to lock the micrometer inadjusted position. With this construction it will be apparent that byloosening the connections of the jacket 54 with the rod 1'7 and byrotating the micrometer in the proper direction, the effective distancebetween the hook portion 18 of the supporting rod .17 and the grindingwheel 8 may be varied to suit the particular work at hand.

It will be readily understood that when several bearings of a crankshaftare ground, they should be ground to the same extent and in order toproduce this result I have provided a gauge member adapted to be broughtinto contact with the lower end of the rod 1'! after the same is set forgrinding the first bearing of a shaft. After this member is set therelative positions of the grinding tool and rod 17 may be altered asnecessary for dismounting the apparatus or for remounting it on anotherbearing, without liability of discrepancy occurring in the extent ofgrinding for the reason that it is only necessary to bring the lower endof the rod 1"! into contact with the gauge in order to insure a settingof the apparatus which is an exact duplication of the original setting.This stop member consists of a bracket 65 clamped to the jacket 54 by aclamping screw 66 and provided with a boss 67 into the lower end ofwhich is threaded a hollow screw 68. Extending through the upper end ofthe boss 67 is the gauge or stop member 69 mounted on the upper end of ascrew '10 which is threaded into the hollow portion of the screw 68.After the rod 1'? is properly adjusted with respect to the grindingwheel 8 the nuts 68 and 69 are properly adjusted so as to bring thegauge member into contact with the lower end of the rod 1'7. Obviously,therefore, after the bearing is ground and the parts released and againremounted on another bearing of the same crankshaft, it is onlynecessary to adjust the micrometer 59 so as to again bring the lower endof rod 1'? into contact with stop 69, to assure an identical grindingand truing of the next bearing of the crank-shaft.

The function and operation ofthe various features of the constructionhave been described in connection with the detailed description of theparts and a repetition of the operation is believed unnecessary exceptto say that in the mounting of the apparatus it is essential that theshafts 16 and 26 be accurately positioned so as to assure the suspensionof the shaft 26 directly below the crankshaft 4 and in parallelism.

From the foregoing description taken in connection with the accompanyingdrawings it will be apparent to those skilled in the art that I havedevised a rather simple yet highly accurate apparatus for regrinding andtruing the bearings of a crankshaft; that the apparat'u'smay be mountedand operated without removing the crankshaft from its position in theengine thereby greatly reducing the cost of regrinding; and that meansare provided for so mounting the grinding apparatus as to assure theproper truing of the bearings.

, In accordance with the patent statutes I have described what I nowbelieve to be the preferred form of construction, but inasmuch as it isquite obvious that various minor changes may be made in the details ofthe construction without departing from the spirit of the invention, itis intended that all such changes be included within the scope of theappended claims.

What I claim is:

1. A grinding and truing apparatus for crankshafts includinga grindingwheel and drive shaft therefor, means for suspending the wheel and shaftfrom the crankshaft, a rod to which the shaft is pivotally connected andmeans associated with the rod for maintaining the wheel and shaft inproper relation to the crankshaft as the latter is rotated in itsbearings.

2. A grinding and truing apparatus for crankshafts including a pivotshaft, means for suspending the pivot shaft from the crankshaft, agrinding wheel and drive shaft connected to said pivot shaft, and meansfor maintaining said pivot shaft in parallelism with crankshaft.

3. A grinding and\truing apparatus for crankshafts including a pivotshaft, means for suspending the pivot shaft from the crankshaft, agrinding wheel and drive shaft supported on said pivot shaft, asecondary shaft parallel to the pivot shaft and rigidly supported fromone or more points, and adjustable connections between said shafts, anda clamp on the pivot shaft for engaging the piston rod.

4. A grinding and truing apparatus for crankshafts including a pivotshaft, means for suspending the pivot shaft from the crankshaft, saidmeans including clamps mounted on the pivot shaft for engaging an end ofone of the piston rods, a grinding wheel and drive shaft supported onsaid pivot shaft, a secondary shaft parallel to the pivot shaft andrigidly supported from one or more points, and adjustable connectionsbetween said shafts.

5. A grinding and truing apparatus for crankshafts including a grindingwheel and drive shaft therefor, means for suspending the wheel and shaftfrom the crankshaft, said means being partly hollow and a connectionwith said suspending means for feeding a liquid to the grinding wheel.

CLARENCE H. CRAFT.

